In addition to the lysines are shown:
- the five characteristic amino acids of a C-DOMAIN [2,3]. Four of them are highly conserved and hydrophobic [4] and are common to the V domain: C23 (1st-CYS), W41 (CONSERVED-TRP), 89 (hydrophobic) and C104 (2nd-CYS) [5]. These four amino acids contribute to the two major features shared by the V and C domains: the disulfide bridge (between the two cysteines 23 and 104) and the internal hydrophobic core of the domain (with the side chains of tryptophan W41 and amino acid 89) [2,3]. The fifth position, 118 is diverse in the C-DOMAIN and is characterized as being an FG loop anchor (whereas it is conserved in the V-DOMAIN and represented by J-PHE 118 or J-TRP 118).
- the CH2 N84.4 site of N-glycosylation (IMGT Lexique Glycosylation) at the top of the DE turn. The asparagine N84.4 is part of a N-glycosylation motif NXS/T (NST in Homo sapiens IGHG1).